Brain Deaths Down, Ditto Organ Donations?

by John Gever John Gever Deputy Managing Editor, MedPage Today
October 28, 2013

Action Points

The proportion of patients with brain injury who progress to neurologic death has decreased over time, especially among those with head trauma.

Note that this improvement may represent improvements in care of brain injury but it also has a negative effect as organ donation after neurologic death is the major source of organs for transplantation.

Neurologic death became progressively less likely among individuals suffering brain injuries in western Canada from 2002 to 2012, with potentially worrisome implications for organ transplantation, researchers said.

The percentage of patients at four referral centers in Alberta and British Columbia with severe brain injuries resulting from trauma, strokes, and other causes fell by half during the 11-year period -- from 8.1% in 2002 to 4.2% in 2012 (P=0.01), according to Andreas H. Kramer, MD, MSc, of the University of Calgary, and colleagues.

Most of the decrease was concentrated in patients with traumatic brain injury (TBI), the researchers indicated online in CMAJ, the Canadian Medical Association journal. In this group, which accounted for more than half of the 2,788 cases in the entire study, the average rate of brain death fell from 6.1% during the first third of the study period compared with 2.8% during the final third (P=0.02).

Brain death rates rose slightly in the 516 patients suffering anoxic brain injury and declined moderately in those with subarachnoid and intracerebral hemorrhage, the researchers found.

Whether the declines overall and in the TBI subgroup represented improvements in treatment was not clear from the study, but Kramer and colleagues suggested that this was probably the case. If so, they noted, it also pointed to a potential problem for the supply of donor organs.

"Patients who have been declared neurologically dead constitute the majority of deceased organ donors in Canada," they noted. "Contemporary data indicate that donation after neurologic death accounts for about one-half of kidney transplants, more than three-quarters of liver transplants, over 90% of pancreas and lung transplants, and all heart and small bowel transplants."

Over approximately the same time period of the study, the researchers added, rates of deceased organ donations have stagnated or declined in some parts of Canada.

"Improvements in the prevention and care of brain injury may contribute to a reduction in the number of organ donors," wrote Kramer (who serves as medical director of southern Alberta's organ donation program) and colleagues.

On the other hand, they noted, life support is sometimes withdrawn in patients with severe neurologic injuries who have not progressed to brain death, with cardiocirculatory death resulting instead. Under some circumstances, these patients may be organ donors -- a practice that could be encouraged, the researchers suggested.

A. Murat Kaynar, MD, MPH, a critical care specialist at the University of Pittsburgh who was not involved with the study, said, "I think it is fairly applicable to the U.S. medical care, especially in terms of the traumatic brain injuries. They observed a decline in mortality; we had the same trend in the U.S. as well."

In the study, Kramer and colleagues drew on prospectively collected data on 2,788 consecutive adult patients treated at the four referral centers for TBI, anoxic brain injury, or intracerebral or subarachnoid hemorrhage starting on Jan. 1, 2002, and ending on June 30, 2012.

Median patient age overall was about 50. Just over a third were female. Median Glasgow Coma Scale scores at admission were 7; the medians for full and modified APACHE II scores was 19-20 and 9-10, respectively. These characteristics did not change markedly during the study period, except that the median APACHE scores each fell by a point.

Of the 2,788 patients tracked in the study, 1,501 had TBI, 516 had anoxic injury, 408 had subarachnoid hemorrhage, and 363 had intracerebral hemorrhage.

When the study interval was divided into thirds -- each 3.5 years long -- average rates of neurologic death overall were 6.9% in the first period, 5.2% in the second, and 4.7% in the third (P=0.1), the researchers found.

Neurologic death resulting from anoxic brain injury became somewhat more common, rising from 4% of patients in the first period to 8.2% in the second and 5.9% in the third (P=0.3).

In a multivariate analysis that adjusted for age and baseline Glasgow score, the odds ratio for neurologic death across the whole cohort was 0.92 (95% CI 0.87-0.98, P=0.006) for each succeeding year in the study.

For the TBI subgroup, the corresponding annualized odds ratio for brain death was 0.87 (95% CI 0.78-0.96, P=0.005).

The other subgroups saw no significant change in the multivariate analysis, with annualized odds ratios in the range of 0.94 to 0.98.

Kramer and colleagues also reviewed patient records to determine whether diagnoses of neurologic death may have been missed. They found seven cases in which it could not be excluded; in one of these, the diagnosis was not made but was clearly possible. Such a diagnosis was considered in the other six prior to withdrawal of mechanical support and cardiocirculatory death.

The findings also suggested that there was not a great increase in the number of patients in long-term vegetative states.

Median durations of ICU stays increased significantly during the study interval -- from 3 days in the first third (interquartile range 1.4-7.8) to 3.8 days in the final third (IQR 1.7-8.6, P<0.001) -- but not enough to suggest that many patients were living weeks or months in unresponsive states.

Median lengths of stay for patients who died in the ICU were 2.1 days during both the first and final thirds of the study period.

Kaynar said the study provided "an interesting perspective" on the uncomfortable relationship between the treatment of brain-injured patients and the availability of organs for transplant.

"They improved the care and the outcome of these patients; in the meantime, they also are decreasing the number of potential donors," he told MedPage Today.

Kramer and colleagues argued that increasing the number of donors would require such tactics as living donations, more donations after cardiocirculatory death, and "innovations aimed at improving the use of donated organs."

Kaynar said that "public awareness of organ transplantation" needs to be emphasized as well.

No external funding for the study was reported.

Kramer and two co-authors reported serving in executive positions with organ transplant programs. No other potential conflicts of interest were reported.

Reviewed by Zalman S. Agus, MD Emeritus Professor, Perelman School of Medicine at the University of Pennsylvania and Dorothy Caputo, MA, BSN, RN, Nurse Planner

More in Neurology

MedPageToday is a trusted and reliable source for clinical and policy coverage that directly affects the lives and practices of health care professionals.

Physicians and other healthcare professionals may also receive Continuing Medical Education (CME) and Continuing Education (CE) credits at no cost for participating in MedPage Today-hosted educational activities.